In the Peruvian Amazon, new highways are opening up forests to large-scale deforestation and invasions of tens of thousands of illegal gold miners, who have polluted rivers with toxic mercury and turned vast areas of forest into virtual moonscapes.

Illegal gold mining in the Peruvian Amazon

The road tsunami

Beyond this, we are living in the most dramatic era of road expansion in human history. The International Energy Agency projects that we will have some 25 million kilometers of new paved roads by 2050 — enough to circle the Earth over 600 times.

Nine-tenths of these new roads will be built in developing nations, including many tropical and subtropical regions that sustain the planet’s biologically richest and most environmentally important ecosystems.

And once all these illegal roads are mapped, the overall impact of roads on forests became clear: 95 percent of all Amazon deforestation occurs within 5.5 kilometers of a legal or illegal road. This shows that roads are having a remarkably powerful impact on the pattern and pace of forest destruction.

The RoadLess Project

In response to the dire need for better road maps, the European Commission’s Joint Research Center in Italy is undertaking a groundbreaking project to map all the legal and illegal roads across the world’s tropical and subtropical forests.

Known as RoadLess, this effort will combine high-resolution satellite imagery with crowdsourcing — using volunteers and some paid workers to map roads by hand.

Humans, it turns out, are very good at discriminating patterns and objects in visually ‘noisy’ backgrounds — easily exceeding the capacity of computers to do so accurately.

The leaders of the RoadLess initiative, researchers Steve Peedell and Frédéric Achard, are beginning to recruit volunteers and others interested in this innovative program.

But if we develop new high-yielding 'supercrops' and farm them intensively, could we feed the world with less land and thereby spare some land for nature? Many have argued in favor of this idea.

A tsunami of oil palm (photo by William Laurance)

But a new study published in the leading journal Science suggests the opposite: supercrops will actually encourage more habitat destruction for agriculture, especially in the species-rich tropics.

The authors argue that new varieties of palm oil, which are highly productive and profitable but grow only in the tropics, are simply going to keep spreading apace. That's because there's so many different uses for palm oil, including for many food items, cosmetics, and biofuels, that demand for it will remain high.

And, as palm-oil production rises, its price will likely fall, meaning that it will increasingly out-compete other oil-producing crops, such as canola (rapeseed), sesame seeds, and peanuts.

This, the authors say, will simply shift the footprint of agriculture from areas such as North America and Europe to mega-diversity regions such as the tropical rainforests of Southeast Asia, Latin America, and Africa.